[FS] Done with CreateFile

src/core/fs/archive_ext_save_data.cpp

@@ -3,6 +3,33 @@
 
 namespace fs = std::filesystem;
 
+CreateFileResult ExtSaveDataArchive::createFile(const FSPath& path, u64 size) {
+	if (size == 0)
+		Helpers::panic("ExtSaveData file does not support size == 0");
+
+	if (path.type == PathType::UTF16) {
+		if (!isPathSafe<PathType::UTF16>(path))
+			Helpers::panic("Unsafe path in ExtSaveData::CreateFile");
+
+		fs::path p = IOFile::getAppData() / "NAND";
+		p += fs::path(path.utf16_string).make_preferred();
+
+		if (fs::exists(p))
+			return CreateFileResult::AlreadyExists;
+			
+		// Create a file of size "size" by creating an empty one, seeking to size - 1 and just writing a 0 there
+		IOFile file(p.string().c_str(), "wb");
+		if (file.seek(size - 1, SEEK_SET) && file.writeBytes("", 1).second == 1) {
+			return CreateFileResult::Success;
+		}
+
+		return CreateFileResult::FileTooLarge;
+	}
+
+	Helpers::panic("ExtSaveDataArchive::OpenFile: Failed");
+	return CreateFileResult::Success;
+}
+
 FileDescriptor ExtSaveDataArchive::openFile(const FSPath& path, const FilePerms& perms) {
 	if (path.type == PathType::UTF16) {
 		if (!isPathSafe<PathType::UTF16>(path))

src/core/fs/archive_ncch.cpp

@@ -1,6 +1,11 @@
 #include "fs/archive_ncch.hpp"
 #include <memory>
 
+CreateFileResult SelfNCCHArchive::createFile(const FSPath& path, u64 size) {
+	Helpers::panic("[SelfNCCH] CreateFile not yet supported");
+	return CreateFileResult::Success;
+}
+
 FileDescriptor SelfNCCHArchive::openFile(const FSPath& path, const FilePerms& perms) {
 	if (!hasRomFS()) {
 		printf("Tried to open a SelfNCCH file without a RomFS\n");

src/core/fs/archive_save_data.cpp

@@ -2,6 +2,11 @@
 #include <algorithm>
 #include <memory>
 
+CreateFileResult SaveDataArchive::createFile(const FSPath& path, u64 size) {
+	Helpers::panic("[SaveData] CreateFile not yet supported");
+	return CreateFileResult::Success;
+}
+
 FileDescriptor SaveDataArchive::openFile(const FSPath& path, const FilePerms& perms) {
 	if (!cartHasSaveData()) {
 		printf("Tried to read SaveData FS without save data\n");

src/core/fs/archive_sdmc.cpp

@@ -1,6 +1,11 @@
 #include "fs/archive_sdmc.hpp"
 #include <memory>
 
+CreateFileResult SDMCArchive::createFile(const FSPath& path, u64 size) {
+	Helpers::panic("[SDMC] CreateFile not yet supported");
+	return CreateFileResult::Success;
+}
+
 FileDescriptor SDMCArchive::openFile(const FSPath& path, const FilePerms& perms) {
 	printf("SDMCArchive::OpenFile: Failed");
 	return FileError;

src/core/services/fs.cpp

@@ -1,5 +1,6 @@
 #include "services/fs.hpp"
 #include "kernel/kernel.hpp"
+#include "io_file.hpp"
 
 #ifdef CreateFile // windows.h defines this because of course it does.
 #undef CreateFile
@@ -32,6 +33,16 @@ void FSService::reset() {
 	priority = 0;
 }
 
+// Creates directories for NAND, ExtSaveData, etc if they don't already exist. Should be executed after loading a new ROM.
+void FSService::initializeFilesystem() {
+	const auto nandPath = IOFile::getAppData() / "NAND"; // Create NAND
+	// TODO: Savedata, SDMC, etc
+
+	if (!std::filesystem::is_directory(nandPath)) {
+		std::filesystem::create_directories(nandPath);
+	}
+}
+
 ArchiveBase* FSService::getArchiveFromID(u32 id) {
 	switch (id) {
 		case ArchiveID::SelfNCCH: return &selfNcch;
@@ -225,7 +236,7 @@ void FSService::createFile(u32 messagePointer) {
 	const u32 filePathType = mem.read32(messagePointer + 16);
 	const u32 filePathSize = mem.read32(messagePointer + 20);
 	const u32 attributes = mem.read32(messagePointer + 24);
-	const u64 bytesToZero = mem.read64(messagePointer + 28); // Bytes to fill with zeroes in the file
+	const u64 size = mem.read64(messagePointer + 28);
 	const u32 filePathPointer = mem.read32(messagePointer + 40);
 
 	log("FS::CreateFile\n");
@@ -240,8 +251,8 @@ void FSService::createFile(u32 messagePointer) {
 	ArchiveBase* archive = archiveObject->getData<ArchiveSession>()->archive;
 	auto filePath = readPath(filePathType, filePathPointer, filePathSize);
 
-	for (auto c : filePath.utf16_string) std::cout << (char)c;
-	Helpers::panic("Tried to create file");
+	CreateFileResult res = archive->createFile(filePath, size);
+	mem.write32(messagePointer + 4, static_cast<u32>(res));
 }
 
 void FSService::getPriority(u32 messagePointer) {

src/emulator.cpp

@@ -49,6 +49,7 @@ void Emulator::runFrame() {
 }
 
 bool Emulator::loadROM(const std::filesystem::path& path) {
+    kernel.initializeFS();
     auto extension = path.extension();
     
     if (extension == ".elf" || extension == ".axf")